Two experiments have been terminated in the last few months. In one, 36 baboons were fed semi-synthetic diets plus 0.1 percent cholesterol; in the other, 24 Vervet monkeys were fed semi-synthetic diets. The lipids of the aorta, liver, lung and bile of these animals are being analyzed. In new experiments baboons or vervets will be fed semi-synthetic diets (14 percent coconut oil; 25 percent protein; 40 percent carbohydrate and 15 percent fiber) in which the type of protein and fiber will also be varied. The influence of these diets on cholesterol absorption, bile acid production, cholesterol body pools, cholesterol turnover time and atherogenesis will be determined. We have reasonable evidence that the most atherogenic carbohydrates are fructose and sucrose. Proteins to be studied will include wheat gluten and soybean protein. Fiber in the diet will include alfalfa and wheat straw.